The invention relates to the manufacture of grids for use in nuclear reactor fuel assemblies. It is particularly suitable for the manufacture of grids for assemblies whose framework comprises end pieces joined by tie-rods in some of the recesses of grids distributed regularly along tie-rods, the other recesses of the grids supporting the fuel elements of the assembly.
The grids generally comprise two sets of strips arranged in two directions at right angles and assembled in half-iron manner in order to define elementary cells traversed by the fuel elements and the tie-rods. The strips are in addition joined, at their periphery, to a belt having the same cross section as the strips. To ensure the cohesion of the grids, the parts are mutually secured at their intersections. This operation is often carried out at the present time by manual brazing, that is to say by a long and tedious process which, moreover, does not guaranty entirely satisfactory reproducibility, even if a positioning jig is used, such as that described in U.S. Pat. No. 4,111,348, for construction of grids whose strips have cut out portions which constitute support springs for the fuel elements, or described in French Pat. No. 2,364,729.